Him personally? Perhaps.
I wouldn't trust him of notifying the police if he witnesses any kind of child abuse though. Especially if the child abuse was committed by a fellow Catholic.
No. I don't trust former Nazis with my kids (once I have some).
Not this Nazi crap again. Like any other German male, Ratzinger automatically became a member of the Hitler Youth at the age of 14... as he was recquired by law. There's not much you could do about it (especially when you're 14). It's not like they're giving you the freedom of choice in a totalitarian state.